Parallax compensating view finder for cameras



A. E. LITTLE PARALLAX COMPENSATING VIEW FINDER FOR CAMERAS Sept. 20, 1949.

2 Sheets-Sheet 1 Filed May 9, 1946 INVENTOR q Zfre EL Z'ZZZe- .Sept. 20, 1949. A. E. LITTLE PARALLAX COMPENSATING VIEW FINDER FOR CAMERAS 2 Sheets-Sheet 2 Filed May 9, 1946 INVENTOR.

\fiZ? BY oqtgs Patented Sept. 20. 1949 BARALLA-XhGQMBENSA'BINQ-VIEW FORICAMERA'ST Alfred 'E, Iiittla Ghicago, E15,. assi'gnor to Busch; Brecision Gameraefiorporation; Ghica'gm; 111;", a1 cnmnmtioniofllllinois Application'May 9;' 1946;;.S erialNo. 668.5176

lxOlaima. {01..8Bir-1a55).

' Thisinvention relates to av-iew finder foruse oncameras and more particularly to a-- novelly constructed view finder capable of compensating: for-parallax effect caused by mounting of the View finder on a camera with its optical axis out of alignment with the optical axis of the camera lens.

In accordance with the foregoing;.it;is there's-- fore an object of this. inventionto. provide a view finder" mountable on a camera, the view findercbeing capable of adjustment for 00111119111 sat'inglfor theeliectof. parallax, .smthatlthe .view asxseeninthe finder. isidentical with thatzsunveyed in the lens...

Another object. of, this-invention is theprovision,;. in a: view. finder. of. the; foregoing character; of} means. for. indicating-: picture sizes. for variousiiocalilengths..of.1enses..

A; further. object. ofthis: invention is the: provision. of aview. finder. of thezforegoing; charac.-

tor. Which:ise.simp1e. in. construction and; easily manipulable evenby. an. inexperienced operator. 1 Qther and further. objects of; the presentgintvention will be. apparent fromthe. following descriptions and claim andare illustrated in the accompanying drawingsiwhich. by way Of?1i11llSI-.-.

tration,. show a. preferredembodiment andz the principle thereof. and which. is; considered; to: be tliebest modecontemplatedrfor applying ethat principle. embodying the same or equivalent principle may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and a purview of the appended claim.

In the drawings.

Fig. 1 is a side elevational view of the camera partially in section and showing my improved view finder mounted thereon.

Referring to the drawings, the numeral 20 Other embodiments of the invention designates generally a bellows type camera, of 55 2: atwell knowntype, on": which my improvedi'viewi linden indicated generally byvthe. numeral Z3 .-is= mounted. The view finder 2-3 comprises a hous mg 2 3 containing a-lens system arranged to :pre-

' sent to the eye of the operator a reducedson.

miniature -view: of that which is surveyed by the camera lens. The housing M: may be: of any; suitable construction; but in the embodimentailf-i lustrated, includes: an-elongated= body portiom tapering from a rectangular: front; portion 25i to:

and blending into a cylindrical rear portion. 23?

containing the eye piece of:- the lens: system;

Mounted in the fronti portion 25 0f thehouse ing forwardly of the lens is-- a mask: madeof i ti ansparentor translucent material and having;

engraved or imprinted thereon,- linesl forming reetangles ingraduated sizes. Each of the rec:- tanglescarriesinsignia which: identifies the same with: relation to a particular focal length for which the-viewfinder ancl camera lens is to be used; The mask 28' is suitably securedto the: housing;as by screws; which pass-through the perforatedcars- 29 integrally attached to the mask The viewfinder 23 may be mounted directl y on the camera or on a plate fixedl to-thecamera, as w-ill be presently I described.

The housing 2 4 is mounted 'om the camera housing bya member iti having a tongue 32 ar-: ranged to be received in the groove defined by spaced lugs 33, 33, attached to the under side of the housing 24. A pin 34 passing through registering perforations provided in the lugs 33, 33, and tongue 32 pivotally connects the housing 24 to the camera and permits pivotal movement of the housing 24 about a horizontal axis in a plane parallel to the plane of the camera lens. The member 3| passes through the top wall of the camera housing and is retained by a lock nut 36, but is pivotally movable about a vertical axis. The view finder housing is thus adapted for pivotal movement in two directions, both vertically and horizontally.

A stud 31 projects through an elongated aperture 38 in the top wall of the camera housing and is in threaded engagement with the view finder housing 24. A spring 39 carried on the stud 31 is confined between the under side of the top wall of the camera housing and the head of the stud 31 and serves to bias the movement of the view finder against the cam structure hereinafter to be described. It will be noted that the aperture 38 is elongated to accommodate the stud 31 in its movement with the housing about the vertical axis of the member 3 I.

A recess M is provided on the under side 0t the housing in the rearward portion thereof. The walls of said recess 4|, as will be seen in Fig. 3, are in parallel relation and angularly inclined relative to the longitudinal axis of the housing. A T-shaped cam element 42, carried on a spindle 43, rotatably mounted at each end, in journals 44 and 45, is arranged to engage the walls of the recess 4|. A lever 45 fixed to the spindle 43' is intended for rotating the spindle in actuating the cam element 42.

It will be seen that as the lever 46 is moved to rotate the spindle 43, the cam element 42 engages both the top and side walls of the recess 4|, causing the rearward portion of the housing 24 to be elevated and simultaneously to swing in a counter-clockwise direction, as viewed in Figure 3. The optical axis of the lens system in the view finder is thereby moved out of parallel relationship with the optical axis of the lens of the camera to thereby provide compensation for the parallax effect resulting from the positioning of the view finder on the camera in spaced relation to the camera lens.

A plurality of chordal surfaces 48 of varying lengths are provided on the periphery of the spindle portion adjacent the journal 45. These chordal surfaces are arranged to be selectively engageable by a spring member 50 mounted on the top wall of the camera for holding the cam element 42 in any one of a number of positions determined by the chordal surfaces. The positions of the chordal surfaces 48 are synchronized with specific positions of the cam element 42, so that each position of the cam element corresponds to a specific distance locating the position of the object to be photographed in relation to the position of the camera lens. Indica identifying the various focal distances within the camera range are disposed along the edges 52 of the slot 53 and a suitable mark is carried on the lever 46 to selectively register with the indicia to indicate to the operator the relative position of the view finder at any particular point of adjustment.

In making an adjustment of the view finder to compensate for parallax, the operator need only move the lever 48 to the indicia mark indicating a particular distance corresponding to the actual distance the object is located from the camera lens. The view finder is thereby moved to the proper position to compensate for parallax effect and to register for the operator the exact view as surveyed by the lens.

I claim:

In a view finder of the character described and having a substantially rectangular housing having a lens system therein, said housing being swivelly mounted at its front end, the herein invention comprising a recess in the bottom face of the housing adjacent its other end, said recess having walls forming a parallelogram in the longitudinal axis of the housing, a rotatable spindle extending beneath said recess, a cam member attached to said spindle and seated in said recess, said cam being T-shaped and having edges engaging the bottom face and side walls of said recess, a lever member on one end of said spindle, whereby said cam member is moved in operative engagement with the bottom face and side walls of said recess, thereby elevating the view finder housing and simultaneously rotating said housing in a counter-clockwise direction.

ALFRED E. LITTLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,312,283 Stahlhuth Aug. 5, 1919 1,566,217 Krone Dec. 15, 1925 1,583,706 Tessier May 4, 1926 1,616,723 Wandersleb Feb. 8, 1927 2,040,422 Austin May 12, 1936 2,123,494 Barnack July 12, 1938 2,191,027 Ort Feb. 20, 1940 2,191,281 Leitz et a1 Feb. 20, 1940 2,232,440 Bisschop Feb. 18, 1941 2,267,811 Brownscombe Dec. 30, 1941 2,322,399 Sperry et al June 22, 1943 2,394,521 Lynn Feb. 5, 1946 FOREIGN PATENTS Number Country Date 85,924 Austria Nov. 10, 1921 548,569 France Oct. 25, 1922 705,829 France Mar. 17, 1931 

